1. Field of the Invention
The present invention relates to processes for the forming, drawing and reduction of tubing.
2. Description of the Prior Art
There are previous inventions for the forming, drawing and reduction of tubing, but none that are equivalent to the present invention.
U.S. Pat. No. 1,318,962, issued on Oct. 14, 1919, to Louis H. Brinkman, discloses an apparatus for drawing metal using a ball die.
U.S. Pat. No. 1,440,527, issued on Jan. 2, 1923, to Louis H. Brinkman, discloses the use of dies wherein balls are provided for operating upon tubing. (See column 1, line 9-11.)
U.S. Pat. No. 2,124,961, issued on Jul. 26, 1938, to Louis H. Brinkman, discloses a metal drawing device, that may be used to reduce the diameter of tubing, with balls arranged in a circle around a mandrel. (See claim 1.)
U.S. Pat. No. 2,669,209, issued on Feb. 16, 1954, to Frederick C. Hoffman, discloses a die assembly for utilizing hydrostatic pressure in a deep body of water for forming sheets, using a ball in a check valve (83 in FIG. 7).
U.S. Pat. No. 3,137,384, issued on Jun. 16, 1964, to Marcel Perret, discloses hydraulic devices for removing tubes drawn on a long mandrel, including a spherical ball in the center of a die cavity (see column 5, lines 34-44). It also discloses a process of feeding the tube through the die and ball set (see column 6, lines 41-56). However, it appears that this is achieved through the use of an internal mandrel.
U.S. Pat. No. 3,662,578, issued on May 16, 1972, to Thomas E. Gleason and Charles C. Ripley, discloses turbulence promoter formation, in which a set of hardened balls in pressed against the surface of a tube to form grooves.
U.S. Pat. No. 4,161,112, issued on Jul. 17, 1979, to Paul E. Stump, discloses a tube drawing technique using a mandrel plug having compound working surfaces.
U.S. Pat. No. 4,383,429, issued on May 17, 1983, to Bruno Ceccacci, discloses an apparatus for forming a point at the end of a metal tube by means of a drawing operation.
U.S. Pat. No. 4,745,787, issued on May 24, 1988, to Dennis H. Sansome and Thiam B. Lim, discloses a plug assembly for use in the plug drawing of tubes.
U.S. Pat. No. 4,947,669, issued on Aug. 14, 1990, to Francis J. Fuchs, Jr., discloses a floating plug for drawing tubing materials (see FIG. 1, column 2, lines 1-31).
U.S. Pat. No. 5,186,033, issued on Feb. 16, 1993, to Alex Nieczyporowicz, discloses an apparatus and method for forming external raised beads on hollow tubing.
U.S. Pat. No. 5,526,663, issued on Jun. 18, 1996, to Jean-Louis Sauvonnet and Franck Delaquerie, discloses devices for the grooving of tubes.
U.S. Pat. No. 5,487,292, issued on Jan. 30, 1996, to Francis J. Fox, discloses tubing being reduced in diameter by the draw die system and the use of a floating plug or mandrel.
U.S. Pat. No. 5,881,592, issued on Mar. 16, 1999, to Ellis Blackwell and Darrell K. Maisel, discloses a floating plug for drawing tubing stock and reducing its diameter (see FIG. 1, column 2, lines 25-57).
U.S. Pat. No. 6,470,723, issued on Oct. 29, 2002, to Tetsuya Sumitomo, Koji Yamamoto and Toshiaki Hashizume, discloses an apparatus for manufacturing an internal grooved tube.
U.S. Patent Application Publication No. 2006/0218985, published on Oct. 5, 2006, to Kazuhito Kenmochi et al., discloses a method for manufacturing a tube with high dimensional accuracy.
Japanese Patent No. 60-187425, published on Sep. 24, 1985, inventor Tatsumi Aritaka, discloses a device that both reduces a metallic tube and forms grooves on the inside of the tube.
Japanese Patent No. 61-286018, published on Dec. 16, 1986, inventors Saeki Chikara, Sato Takuyuki and Iozaki Akio, discloses a device that both reduces a pipe and forms grooves on the inside of the pipe.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.